Grammar Girl here.

Today, guest rider Bonnie Tranga helps us understand modifiers that come at the beginning of a sentence.

Bonnie says, as a guest rider, I plan to talk about two kinds of troublesome modifiers

that begin a sentence.

Like many of you, Suzanne wants to know if it's okay to start a sentence with an as-phrase,

as in the sentence, as citizens of China, we enjoy eating noodles.

Of course you can, but you have to pay attention to what comes after the introductory phrase.

In the phrase, as citizens of China, the word as is a preposition that means in the role

of or in the capacity of.

But the whole phrase acts as an adjective to modify what comes next, in this case we.

I often find myself saying sentences like, as a copy editor, I must correct many mistakes.

Now you try, just plug in the specifics for your own job, as a whatever, I do whatever.

A hominspector might say, as a hominspector, I have to watch out for bats in the attic.

So feel free to start a sentence with an as phrase.

But just be careful that you put the person that the as phrase refers to right after the job name.

It would be incorrect to say, as a hominspector, bats sometimes fly in my face when I'm in the attic.

That's called a misplaced modifier, because the modifier, the as phrase, mistakenly modifies bats.

This is a very common error that I as a copy editor see.

Notice in that last sentence, I said, I as a copy editor, that sentence, although a bit awkward, is correct,

because I is next to the as phrase.

An as phrase can sneak up on you in the middle or the end of a sentence, too.

So make sure you put the correct person after the as phrase, no matter where it appears.

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